playing, learning, and being outdoors in Cambridge, Mass.

Will you be having dental floss with your garlic mustard today, sir?

Garlic Mustard Ball at Fresh Pond Day. Fighting invasives was never this fun.

They do learn stuff, though, because it is in the nature of their being to suck up information like a marsh.

Back in the fall of 2012, when I was muddling through the particular big muddy of what to do with a gaggle of second graders in a splendid semi-wild urban habitat right smack next door to their school, I went to an outdoor fungi hike led by mycologist Lawrence Millman. I got a little bit bit by the mushroom bug, and under all that pinestraw I found —in addition to some striking specimens—myself in an aha! moment.

The role of fungi in ecosystems isn’t rocket science but it’s pretty complex, with way more detail than I’m currently capable of synthesizing.

Cambridge School Committee Member Patty Nolan, at right, joins the Tree Team in Garlic Mustard Ball.

Well, as I get older I get more comfortable with beginner’s mind. I applied my rudimentary knowledge of Montessori pedagogy to what I did know, and many yards of dental floss later, a handful of kids not only know about mycorrhizal relationships but can demonstrate it to other kids.

I took a simple ball game my ten-year-old told me she’d played at gym and made it into a metaphor for how fungi and trees interact. Before showing a new group of kids the game itself, I do another kind of demonstration. One child gets to be a tree, another is the fungus. I give the “fungus” a big tangle of dental floss and explain that fungal mycelia are everywhere underneath the ground, impossible (nearly always) to see, running many miles in length. Some fungi interact with tree roots (the Fungus Kid moves the dental floss over to the shoes of the Tree Kid), providing better ability to absorb minerals and moisture. The tree also provides carbohydrates to the fungus (Tree Kid hands a piece of bread or cookie to the Fungus Kid), which as a non-photosynthesizing organism can’t otherwise make its own food.

The final step in the pre-ball-game demonstration is to get out a jar of mustard and a garlic clove and put it on the mess of dental floss, remove the dental floss, and tell the kids that the garlic mustard plant interferes with that process and the benefits the tree earns from the mycorrhizal relationship. End of high drama. I guess I should have the Fungus Kid keel over at the end. I’ll remember that when our next round of the club that starts in the fall and the fungi are in visible abundance.

Our club kids demonstrated garlic mustard ball at Fresh Pond Day, with a random assortment of unfortunate adults, gleeful younger siblings, and passersby of all ages.

Club member (second-grader) explaining to the throngs the symbolic nature of the game. Yes, that’s dental floss in his left hand.